Apparatus for continuous clarification



Jan. 5, 1943,

J. R. OSUNA APPARATUS Fon CONTINUOUS GLARIFICATION Filed July l0, 1941 3 Sheets-Sheet 2 JNVENTOR. B ,l gd/"WM MM Mvg/fw? ArroR/vfys Jan. 5, 1943. J. R. osuNA APPARATUS FOR CONTINUOUS CLARIFICATION Filed July 10, 1941 3 Sheets-Sheet 5 ATTORNEYS Patented Jan. 5, 1943 OFFICE APPARATUS FOR CONTINUOUS CLARIFICATION Jos Ramon Osuna, Marianao, Cuba Application July In Cuba 10, 1941, Serial No. 401,824

July 30, 1940 3 Claims. (Cl. IWI- 13) The method heretofore employed in the manutacture of sugar and particularly in the sugar reilning operation, consists in subjecting the syrups formed by dissolution of washed or afiiinated raw sugar to a purliication process which is carried out as follows: The washed or aminated sugar is dissolved in water in tanks provided with agitators to form a syrup with a density of 60 Brix, and the syrup obtained is purified by treatment with chemical agents and heat. The solutions thus treated are discharged into open tanks (defactors) to be subjected to clarification by decantation. The number oi detactors or tanks is dependent upon the amount ci material to be treated in 24 hours and upon the time required for obtaining the clarification in each tank. In the case of dense solutions which are the ones being usually treated at sugar reneries, the average time required for decantation varies from 45 to 60 minutes and sometimes more, depending upon the liquid level, density and temperature.

The processes heretofore employed require the temperature to be raised sometimes even to above 216 F'. in order that the fioculesformed may rapidly ascend to the liquid surface and properly separate after they have overcome the weight of the liquid upon them. It is Just in this stage 4that the so-called, manufacturing losses occur, which are caused by the heat affecting the sucrose and tending to invert it thereby yielding a greater percentage of molasses to the factory; heat also causing the liquid to become darkened on account of the candied condition of sucrose, and the use of additional decoloring agents being required in a further dccoloring operation in order to obtain a No. 1 liquor from which refined sugar is obtained as the final product.

This invention has for its object to provide a method of and apparatus for subjecting the noncrystaliized sugar Syrups, solutions or juices to a continuous clarification at a rate of vacuum between 29" and 0", a temperature diflerence 'oi' 3 C. or more below the corresponding vacuum temperature, being used. Said 3 C. temperature diiierence is used for the purpose of preventing the liquid from boiling for it is a well known fact that every boiling point according to the pressure acting upon same.

The advantages possessed by my clarification method and apparatus are, in the case or rennery syrups, that these can be ciariiied at a lower temperature than is at present required, without danger ci increasing the darkness or color. and an increase of velocity is attained which permits to treat a larger quantity of material inthe same period of time with smaller tanks and in ashorter pe able reduction is obtained version which occur under The invention is described with reference to the figures or the accompanying drawings, of which:

Fig. 1 is a diametral vertical sectional view o! a continuous clarifier and attachments thereof for carrying out the clarification method being the subject-matter of this invention.

Fig. 2 is a top plan view of same.

Fis. 3 is a longitudinal vertical sectional view ci the level regulator on line 3-3 of Fig. 2.

Fig. 4 is a fragmentary outer elevational view of the tray forming the upper chamber of the clarier.

Fig. 5 is a fragmentary top plan view of the same tray.

Fig. 6 is a vertical cross-section view on line 8-6 ci Fis. 4.

Fig. 'l is a detailed view showing in a broken longitudinal vertical section the level regulator annexed to the continuous clariiier and the latters connection with the former.

Fig. 8 is a detailed edge view of an arm agitator used for the liquid surface with the clarier.

Fig. 9 is an elevational detailed view or the same arm agitator.

Fig. i0 is a vertical cross-section detailed view on line l-l oi Fig. 9.

The method of clarication being the object of this invention consists in clarifying liquids at a pressure below the atmospherical pressure within sealed tanks having compartments within which the liquid flows upwardly, impurities deposited above the liquid level being eliminated and the partial withdrawal or claried liquid being elected at the lowest zone of each compartment, in contrast to the clarification methods at present known in which the liquid flows downwardly, the mud is withdrawn at the bottom and the partial removal oi clarified liquid is eiiected at the upper zone of each compartment.

clariiier device which device consists of a cylindrical tank i closed at the top, the upper portion is conical in shape and its bottom portion is in the shape of an inverted cone. The bottom of tank i is provided with a register opening 2 having a pressure cover and a feed-tube l for the,

liquid to be clarified. said feed-tube I ending in the form oi' an inverted syphon at a predetermined height from the bottom. and the bottom of the tank I has also a central opening and therein a discharge tube l provided with controlling valve 5. The tank is divided int riorly into a lower flocculation chamber 6, an upper; sludge discharge chamber 1 and an intermediate series of clarifying chambers 8, by means of a plurality ci trays 9 oi' frusto-conical shape or sloping from the center to the periphery. Said trays are secured at their outer edge to the pe ripherial wall of tank I and each has an upstanding cylindrical portion 8' at their upper open portion to permit the liquid to pass upwards along the central line of tank I. Each compartment B is provided at the peripherial wall of tank I with a register opening III for cleaning purposes at one side thereof and at the otherside each compartment has a small opening and a discharge tube II provided with a controlling valve I2 for the liquid clarined in the lowest zone of each compartment. The'tray 9 serving as a bottom portion for the sludge upper discharge chamber 1 has avertical cylindrical portion 9" which is higher than the vertical cylindrical portions il' of the lower trays and is provided with four openings I3 near its upper portion which is crossed by a diametral partition Il dividing the cylindrical portion in two half portions laterally opened in abottom inclined radial conduit I5 (Fig. 4) terminating at the peripherie] wall of tank I in an opening provided with a discharge tube I6 for the sludge separated from the liquid surface. tank I is rotatably mounted on a bearing I1 a vertical shaft Il supported at its lower end on a bearing I! integral at the middle portion of partiticn Il. The vertical shaft Il is provided at its lower end with agitator arms formed by vertical blades 20 in diametral alignment from which other vertical parallel blades 22 are hanging through rings 2i, the vertical shaft Il being rotated at a very slow speed by means of a horiaontal helicoidal wheel 2l actuated by a worm gear 2l coupled to the shaft of an electric motor 25 supported on the upperportion of tank I. The upper portion of tank I has a large opening 26 for connection with the pipe 21 communicating At the upper central portion of the with a vacuum condense; which is not shown, so

and at said upper portion of tank I there are also disposed a vacuum manometer 2l and a tube with a controlling valve I9 for communicating the interior of tank I with the atmosphere, when desired.

The tubes Il for discharging the clarified liquid in the lowest -irene of the intermediate compartments 8 and the upper chamber 1 are connected to vertical tubes Il thenumber of which is e ual to that of tu II, three of said tubes q bes tank being sealed, the system operates at a pres-v beingindicated in the drawings. Said tubes I0 rise up to a predetermined height above the bottom portion of a closed box 8| supported on a bracket? I2 secured exteriorly to the peripherie! wall of tank I, and each tube III is provided with c5 a controlling valve 30. 0n the upper, portions oi' the three tubes 3l are slidably mounted cylindrlcal sleeves 33 which t on tubes ll and form at their upper ends discharge openings the height of which is adjusted by means of clamps 34 secured to the sleeves II' and connected tovertical screws 35 threadedly mounted in 'nuts Il rotatably mounted on the upper portion of box 3l, the object of said three vertically slidable discharge sleeves l! belng to control the discharge height of the liquid falling fromtubes 8l into box II and therefore the level of the liquid within the upper chamber 1 of tank I. The box II is provided with a clarified liquid discharge tube 31 leaving from the bottom of the box and leading downwards to end in a collector tank (not shown) disposed far beneath the tank I said collector tank being completely sealed to maintain the required vacuum in the system. The tube 31 has a horizontal branch tube I8 connected to the three vertical tubes I0 by means 0f the horizontal tube 3B and said tube 38 in turn extends to form a branch tube bent twice at an angle as indicated by Il and has a controlling valve II beneath the bottom ci' tank I. Through the bottom of tank I two tubes l2 each having a controlling valve 43 extend upwards to be connected at the end of the branch tube 40 and terminate at their upper open end near the tray 8 which serves as a cover for the ilocculation chamber I. the function of said tubes being to serve as outlets for the clarified liquid when the clarinet is emptied for cleaning purposes. The level controlling box 3l is in communication with the vacuum pipe 21 through a tube M having a controlling valve I5 and leading from the upper portion of the box Il.

'I'he method of continuous vacuum clarification Is carried out by means of the described apparatus, as follows: The liquid to be clarled enters through feed-tube l into the bottom portion oLtank I and arises into ilocculation chamber 6. The first ilocules carried along by the liquid to the upper edge of ,the upstanding cylindrical portion 9' of the lower tray 0 separate from the liquid. Said cylindrical portion l' and lowerl tray 9 discharge the liquid and the flocules into the lower intermediate compartment l wherein additional flocules separate. 'Ihe liquid and the separated flocules pass into the upper intermediate compartment 8 and from the latter into the upper chamber 1 wherein the liquid level isregulated by previous adjustment of cylindrical sleeves 33 of tubes SII through suitable action by the screws 35. Agitator arms M are rotated on the surface of the liquid in chamber 1, which sweep the ilocuies separated in the various compartments and deposited on the surface of the liquid within upper chamber I and lead them toward the bottom inclined radial conduit I5 which carries them to discharge tube Il through which the sludge separated from the liquid within tank I is withdrawn. The clarliled liquid occupying the lowest zone of each compartment l and upper chamber 1 by reason of the ilocules tending to arise on account ot their lighter condition, is withdrawn through tubes II and discharged through vertical tubes 30 within the box 3| and nnally collected through vertical tube I1 in the aforesaid collector tank (not shown).V

The tank II box II and clarified liquid collector sure below atmospherical pressure. preferably at a pressure of 35 and a diiference of 3 C.

in temperature is used below the temperature' coloring agents in the decoioring operation in order to obtain the so-called No. l liquor and the production of a greater percentage of moiasses in the crystallization operation in which refined sugar is obtained.

It is obvious that the operating details of the method and the construction details ci the apparatus for carrying it out can be varied within certain limits without thereby affecting Vthe essential charbcter of the invention within the scope of the appended claims.

What I claim is:

l. An apparatus for continuous clarification, comprising a cylindrical tank divided by means oi' trays of frustro-conical shape sloping from the middle portion to the periphery in an upper chamber for sludge separation, a lower liquid entering and initial ilocculation chamber, and a plurality of intermediate compartments for addi-` tional clarication upwards. a feed tube for the liquid to be clarified in the lower chamber, said trays having a large opening ai'. the center of their upper portion fromV the edge of which rises a cylindrical tube, a sludge discharge tube above the liquid level in the upper chamber means for maintaining reduced pressure in Vthe tank, and tubes for withdrawal of clariiied liquid at a point kof the lowest zone of each compartment.

2. An apparatus for continuous clarification, comprising a cylindrical tank divided by means of circular trays of frustro-conical shape sloping from the middle portion to the periphery in an upper sludge separation chamber, a lower chamber for liquid entrance and initial iloccuiatlon and intermediate compartments tor additional clarincation upwards, a feed tube for the liquid to be clarified in the lower chamber. said trays having a large opening at the center of their upper portion from the edge of which rises a cylindrical tube, agitator'arms rotatably mountedonaverticalshaft inthe upper chamber at a level adjacent the liquid surface. means for maintaining reduced pressure in the tank, a radial conduit having-an inclined bottom portion situated beneath the agitator arms to receive the sludge gathered on the liquid surface, a sludge discharge tube connected to the tank wall at the end of the radial conduit, and tubes i'or withdrawing clariiled liquid at a point of the lowest zone of each compartment.

3. An apparatus for continuous clarification. comprising a cylindrical tank divided by means of circular trays of frusta-conical shape sloping from the middle portion to the periphery in an upper sludge separation chamber, a lower chamber for liquid entrance and initial ilocculation and intermediate compartments for additional clariiication upwards. said trays having a large opening at the center of their upper portion from the edges of which rises a cylindrical portion which does not reach the immediate upper tray,

a feed tube for the liquid to be claried in the lower chamber, which tube endsV in the shape of4 an inverted syphon at a predetermined height above the tank bottom, agitator arms rotatably mounted on a vertical shaft in the upper chamber at a level adjacent the liquid surface, a radial conduit having an inclined bottom portion situated beneath the agitator arms to receive the sludge gathered on the liquid surface. a sludge discharge tube connected to the tank wall at the end of the radial conduit, tubes for withdrawal of clarined liquid at a point of the lowest sone of each intermediate compartment and upper chamber, means for maintaining reduced `pressure in the tank and outer means for regulating the surface level of the liquid within the tank, said means consisting of a box enclosingthe upper portions of the clariiled liquid withdrawal tubes and cylindrical sleeves slidabiy adjusted on the openings of the withdrawal tubes for regulating the discharge tall height within the .Josn RAMN osUNA. 

